/*
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html.
 *
 * This file is a derivative of code released under the terms listed below.
 *
 */
/*
 *
 * Copyright (c) 2009-2012,
 *
 *  Jonathan Bardin     <astrosus@gmail.com>
 *  Steve Suh           <suhsteve@gmail.com>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The names of the contributors may not be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 *
 */

package com.ibm.wala.dalvik.classLoader;

import com.ibm.wala.dalvik.dex.instructions.Instruction;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * Collection of {@code Instruction} which allows getting an instruction from its table index id or
 * from its bytecode index. Removing an element is not allowed.
 */
public class InstructionArray implements Collection<Instruction> {
  List<Instruction> instructions;
  Map<Integer, Integer> pc2index;
  List<Integer> index2pc;

  public InstructionArray() {
    instructions = new ArrayList<>();
    pc2index = new HashMap<>();
    index2pc = new ArrayList<>();
  }

  @Override
  public boolean add(Instruction e) {
    boolean ret = instructions.add(e);

    if (ret) {
      pc2index.put(e.pc, size() - 1);
      index2pc.add(e.pc);
    }

    return ret;
  }

  @Override
  public boolean addAll(Collection<? extends Instruction> c) {
    boolean ret = false;

    for (Instruction instruction : c) {
      ret |= add(instruction);
    }

    return ret;
  }

  @Override
  public boolean contains(Object o) {
    return instructions.contains(o);
  }

  @Override
  public boolean containsAll(Collection<?> c) {
    return instructions.containsAll(c);
  }

  @Override
  public boolean equals(Object o) {
    return instructions.equals(o);
  }

  @Override
  public int hashCode() {
    return instructions.hashCode();
  }

  public int indexOf(Object o) {
    return instructions.indexOf(o);
  }

  @Override
  public boolean isEmpty() {
    return instructions.isEmpty();
  }

  @Override
  public Iterator<Instruction> iterator() {
    return instructions.iterator();
  }

  @Override
  public void clear() {
    throw new UnsupportedOperationException();
  }

  @Override
  public boolean remove(Object o) {
    throw new UnsupportedOperationException();
  }

  @Override
  public boolean removeAll(Collection<?> c) {
    throw new UnsupportedOperationException();
  }

  @Override
  public boolean retainAll(Collection<?> c) {
    throw new UnsupportedOperationException();
  }

  @Override
  public int size() {
    return instructions.size();
  }

  @Override
  public Object[] toArray() {
    return instructions.toArray();
  }

  @Override
  public <T> T[] toArray(T[] a) {
    return instructions.toArray(a);
  }

  /**
   * @param pc the byte code index.
   * @return The index of the instruction of given byte code index
   */
  public int getIndexFromPc(int pc) {
    if (!pc2index.containsKey(pc) && pc2index.containsKey(pc + 1)) {
      pc++;
    }
    return pc2index.get(pc);
  }

  /**
   * @param index the instruction index.
   * @return The byte code address of the instruction index
   */
  public int getPcFromIndex(int index) {
    return index2pc.get(index);
  }

  /**
   * @return The instruction from its id.
   */
  public Instruction getFromId(int id) {
    return instructions.get(id);
  }

  /**
   * @return The instruction from its pc.
   */
  public Instruction getFromPc(int pc) {
    return instructions.get(pc2index.get(pc));
  }
}
